Blinded comparison of esophageal capsule endoscopy versus conventional endoscopy for a diagnosis of Barrett's esophagus in patients with chronic gastroesophageal reflux

Expanding beyond endoscopy: A review of non-invasive modalities in Barrett’s esophagus screening and surveillance

Barrett’s esophagus (BE) is a condition that results from replacement of the damaged normal squamous esophageal mucosa to intestinal columnar mucosa and is the most significant predisposing factor for development of esophageal adenocarcinoma. Current guidelines recommend endoscopic evaluation for screening and surveillance based on various risk factors which has limitations such as invasiveness, availability of a trained specialist, patient logistics and cost. Trans-nasal endoscopy is a less invasive modality but still has similar limitations such as limited availability of trained specialist and costs. Non-endoscopic modalities, in comparison, require minimal intervention, can be done in an office visit and has the potential to be a more ideal choice for mass public screening and surveillance, particularly in patents at low risk for BE. These include newer generations of esophageal capsule endoscopy which provides direct visualization of BE, and tethered capsule endomicroscopy which can obtain high-resolution images of the esophagus. Various cell collection devices coupled with biomarkers have been used for BE screening. Cytosponge, in combination with TFF3, as well as EsophaCap and EsoCheck have shown promising results in various studies when used with various biomarkers. Other modalities including circulatory microRNAs and volatile organic compounds that have demonstrated favorable outcomes. Use of these cell collection methods for BE surveillance is a potential area of future research.

New endoscopic capsule vs upper gastrointestinal endoscopy in preoperative work-up of obese candidate for bariatric surgery: Relevance of a pilot study in the COVID-19 era

Background and study aims  Obesity represents a major health concern; bariatric surgery is the most effective treatment reducing and maintaining weight loss. The role of a routine esophagogastroduodenoscopy (EGD) prior bariatric surgery is still debated. Moreover, in this scenario of COVID-19 pandemic, EGD is even more questionable due to the procedural risk of viral transmission. A new model of video-endoscopic capsule (VEC) recently has been introduced as a good alternative to the EGD. The aim of this study was to determine if this new capsule is an adequate diagnostic alternative to EGD in the work-up of patients selected for bariatric surgery, particularly in the setting of COVID-19. Patients and methods  From January to November 2020, 27 patients selected for bariatric surgery were enrolled in this pilot study to assess for noninferiority of VEC compared to EGD in detection of upper gastrointestinal disease. Results  VEC had sensitivity, specificity, and positive and negative predictive values in identification of significant lesions of 91.3 %, 83.33 %, 98.01 %, and 51.57 %, respectively, compared with EGD as the standard criterion. The accuracy was 90.51 % (95 % CI, 73.75 %-98.18 %) and the chi-square statistic is 0.1153 ( P  = 0.73). Conclusions  Our report confirms the diagnostic noninferiority of VEC in preoperative work-up of patients selected for bariatric surgery, compared to EGD. This is very important, particularly during the COVID-19 pandemic, given the high risk of contamination with EGD. Larger multicenter studies are required to confirm our preliminary results.

Current status and future developments of upper gastrointestinal tract capsule endoscopy

Capsule endoscopy has been widely used for the diagnosis of small bowel diseases due to its safety, noninvasiveness, and acceptability. Despite the potential benefits of capsule endoscopy, there are obvious challenges to capsule endoscopy application in the upper gastrointestinal tract, due to the fast transit speed in the esophagus and large space of the gastric cavity. With the development of innovative technologies, such as magnetic navigation and tethered capsule endoscopy, the indications for capsule endoscopy have recently been expanded. Various capsule endoscopes have been applied to clinical practice, and several state-of-the-art research-oriented designs and devices provide hope for further use in the diagnosis of upper gastrointestinal diseases. In this review, we will summarize the current status and future developments of upper gastrointestinal tract capsule endoscopy.

Video Capsule Endoscopy Beyond the Gastrointestinal Suite

Video capsule endoscopy has been proven to be a beneficial tool to inspect the gastrointestinal lumen but its true impact may lie in utilization outside of traditional gastroenterology settings such as in the emergency room, the intensive care unit, and outpatient settings. Some advantages of video capsule endoscopy are that its administration does not require special training, patients do not require anesthesia, and videos can be shared with off-site consultants.

Systematic review and meta-analysis of prevalence and risk factors for Barrett's esophagus

BACKGROUND AND AIMS

Although screening for Barrett's esophagus (BE) is recommended in individuals with multiple risk factors, the type and number of risk factors necessary to trigger screening is unclear. In this systematic review and meta-analysis, we aimed to assess the relationship between number of risk factors and prevalence of BE.

METHODS

Through October 17, 2018 we searched studies that described the prevalence of BE in the general population and based on presence of risk factors that included GERD, male gender, age >50 years, family history of BE and esophageal adenocarcinoma, and obesity (defined as body mass index >35). Risk of BE based on number of risk factors was assessed using meta-regression while controlling for potential confounders.

RESULTS

Of 2741 studies, 49 were included in the analysis (307,273 individuals, 1948 with biopsy specimen-proven BE). Indications varied by study. The prevalence of BE for various populations was as follows: low-risk general population, .8% (95% confidence interval [CI], .6%-1.1%); GERD, 3% (95% CI, 2.3%-4%); GERD plus presence of any other risk factor, 12.2% (95% CI, 10.2%-14.6%); family history, 23.4% (95% CI, 13.7% -37.2%); age >50, 6.1% (95% CI, 4.6%-8.1%); obesity, 1.9% (95% CI, 1.2%-3%); and male sex, 6.8% (95% CI, 5.3%-8.6%). Prevalence of BE varied significantly between Western and non-Western populations. In a meta-regression, controlling for the region of the study, age, and gender, there was a positive linear relationship between the number of risk factors and the prevalence of BE.

CONCLUSIONS

Results of this study provide estimates of BE prevalence based on the presence and the number of risk factors. These results add credence to current guidelines that suggest screening in the presence of multiple risk factors.

Novel Screening Tests for Barrett's Esophagus

PURPOSE OF REVIEW

There has been an exponential increase in the incidence of esophageal adenocarcinoma (EAC) over the last half century. Barrett's esophagus (BE) is the only known precursor lesion of EAC. Screening for BE in high-risk populations has been advocated with the aim of identifying BE, followed by endoscopic surveillance to detect dysplasia and early stage cancer, with the intent that treatment can improve outcomes. We aimed to review BE screening methodologies currently recommended and in development.

RECENT FINDINGS

Unsedated transnasal endoscopy allows for visualization of the distal esophagus, with potential for biopsy acquisition, and can be done in the office setting. Non-endoscopic screening methods being developed couple the use of swallowable esophageal cell sampling devices with BE specific biomarkers, as well as trefoil factor 3, methylated DNA markers, and microRNAs. This approach has promising accuracy. Circulating and exhaled volatile organic compounds and the foregut microbiome are also being explored as means of detecting EAC and BE in a non-invasive manner. Non-invasive diagnostic techniques have shown promise in the detection of BE and may be effective methods of screening high-risk patients.

Current and Future Use of Esophageal Capsule Endoscopy

Capsule endoscopy can be a diagnostic option for patients with esophageal diseases who cannot tolerate esophagogastroduodenoscopy.Functional modifications of the capsule allow for thorough examination of the esophagus. Esophageal capsule endoscopy has so farfailed to show sufficient performance to justify the replacement of traditional endoscopy for the diagnosis of esophageal diseasesbecause the esophagus has a short transit time and common pathologies appear near the esophagogastric junction. However,technological improvements are being introduced to overcome the limitations of capsule endoscopy, which is expected to become agood alternative to conventional endoscopy.

Alternatives to Traditional Per-Oral Endoscopy for Screening

Barrett's esophagus (BE) predisposes patients to esophageal adenocarcinoma. 3 to 6% of individuals with gastro-esophageal reflux disease are estimated to have BE but only 20 to 25% of BE patients are currently diagnosed. The current gold standard for diagnosis of BE is per-oral upper GI endoscopy. As this is not suitable for large-scale screening, a number of alternative methods are currently being investigated: transnasal and video capsule endoscopy, endomicroscopy, cell collection devices like the cytosponge and biomarkers. Some of these are promising, however, well powered studies carried out in relevant screening populations are needed.

Asia-Pacific consensus on the management of gastro-oesophageal reflux disease: an update focusing on refractory reflux disease and Barrett's oesophagus

OBJECTIVE

Since the publication of the Asia-Pacific consensus on gastro-oesophageal reflux disease in 2008, there has been further scientific advancement in this field. This updated consensus focuses on proton pump inhibitor-refractory reflux disease and Barrett's oesophagus.

METHODS

A steering committee identified three areas to address: (1) burden of disease and diagnosis of reflux disease; (2) proton pump inhibitor-refractory reflux disease; (3) Barrett's oesophagus. Three working groups formulated draft statements with supporting evidence. Discussions were done via email before a final face-to-face discussion. We used a Delphi consensus process, with a 70% agreement threshold, using Grading of Recommendations Assessment, Development and Evaluation (GRADE) criteria to categorise the quality of evidence and strength of recommendations.

RESULTS

A total of 32 statements were proposed and 31 were accepted by consensus. A rise in the prevalence rates of gastro-oesophageal reflux disease in Asia was noted, with the majority being non-erosive reflux disease. Overweight and obesity contributed to the rise. Proton pump inhibitor-refractory reflux disease was recognised to be common. A distinction was made between refractory symptoms and refractory reflux disease, with clarification of the roles of endoscopy and functional testing summarised in two algorithms. The definition of Barrett's oesophagus was revised such that a minimum length of 1 cm was required and the presence of intestinal metaplasia no longer necessary. We recommended the use of standardised endoscopic reporting and advocated endoscopic therapy for confirmed dysplasia and early cancer.

CONCLUSIONS

These guidelines standardise the management of patients with refractory gastro-oesophageal reflux disease and Barrett's oesophagus in the Asia-Pacific region.

The Role of Esophagogastroduodenoscopy Surveillance for Patients with Barrett Esophagus

Approximately 10% to 15% of patients who experience chronic gastroesophageal reflux disease have Barrett esophagus, which is associated with an increased risk of esophageal adenocarcinoma. If symptoms persist after 8 weeks of adhering to treatment and lifestyle modifications, or if alarm symptoms develop, patients should be referred for screening upper endoscopy. Those with evidence of Barrett esophagus with dysplasia should be monitored in an endoscopic surveillance program, and those with high-grade dysplasia should consider surgical treatment.

Advances in the management of Barrett's esophagus and early esophageal adenocarcinoma

The incidence of esophageal adenocarcinoma (EAC) has markedly increased in the United States over the last few decades. Barrett’s esophagus (BE) is the most significant known risk factor for this malignancy. Theoretically, screening and treating early BE should help prevent EAC but the exact incidence of BE and its progression to EAC is not entirely known and cost-effectiveness studies for Barrett’s screening are lacking. Over the last few years, there have been major advances in our understanding of the epidemiology, pathogenesis and endoscopic management of BE. These developments focus on early recognition of advanced histology and endoscopic treatment of high-grade dysplasia. Advanced resection techniques now enable us to endoscopically treat early esophageal cancer. In this review, we will discuss these recent advances in diagnosis and treatment of Barrett’s esophagus and early esophageal adenocarcinoma.

Screening for Barrett's Esophagus

The large increase in the incidence of esophageal adenocarcinoma in the West during the past 30 years has stimulated interest in screening for Barrett's esophagus (BE), a precursor to esophageal cancer. Effective endoscopic treatments for dysplasia and intramucosal cancer, coupled with screening programs to detect BE, could help reverse the increase in the incidence of esophageal cancer. However, there are no accurate, cost-effective, minimally invasive techniques available to screen for BE, reducing the enthusiasm of gastroenterologists. Over the past 5 years, there has been significant progress in the development of screening technologies. We review existing and developing technologies, new minimally invasive imaging techniques, nonendoscopic devices for cell collection, and biomarkers that can be measured in blood or stool samples. We discuss the status of these approaches, data from clinical studies of their effects, and their anticipated strengths and weaknesses in screening. The area is rapidly evolving, and new tools will soon be ready for prime time.

Barrett's oesophagus: how should we manage it?

Endoscopic surveillance remains the core management of non-dysplastic Barrett's oesophagus, although questions regarding its efficacy in reducing mortality from oesophageal adenocarcinoma have yet to be definitively answered, and randomised trial data are awaited. One of the main goals of current research is to achieve risk stratification, identifying those at high risk of progression. The recent British Society of Gastroenterology (BSG) guidelines on surveillance have taken a step in this direction with interval stratification on clinicopathological grounds. The majority of Barrett's oesophagus remains undiagnosed, and this has led to investigation of methods of screening for Barrett's oesophagus, ideally non-endoscopic methods capable of reliably identifying dysplasia. Chemoprevention to prevent progression is currently under investigation, and may become a key component of future treatment. The availability of effective endotherapy means that accurate identification of dysplasia is more important than ever. There is now evidence to support intervention with radiofrequency ablation (RFA) for low-grade dysplasia (LGD), but recent data have emphasised the need for consensus pathology for LGD. Ablative treatment has become well established for high-grade dysplasia, and should be employed for flat lesions where there is no visible abnormality. Of the ablative modalities, RFA has the strongest evidence base. Endoscopic resection should be performed for all visible lesions, and is now the treatment of choice for T1a tumours. Targeting those with high-risk disease will, hopefully, lead to efficacious and cost-effective surveillance, and the trend towards earlier intervention to halt progression gives cause for optimism that this will ultimately result in fewer deaths from oesophageal adenocarcinoma.

Capsule endoscopy--not just for the small bowel: a review

Video capsule endoscopy is being increasingly used to investigate the esophagus and colon as well as the small bowel. With the advancement of technology used in capsule endoscopy there have been marked improvements in diagnostic rates for colon capsule endoscopy in the detection of colonic polyps and colorectal cancer. It is also being increasingly used in the field if inflammatory bowel disease to investigate for mucosal inflammation and could potentially be used to assess mucosal healing. It also has role in completing the evaluation of colonic pathology in those in whom colonoscopy is incomplete. Esophageal capsule is preferred by patients over esophagogastroduodenoscopy (EGD) but as yet does not rival EGD in terms of diagnostic accuracy however the advent of magnetically steerable capsules may improve this. This review covers advances in the field of colon and esophageal capsule endoscopy; it covers diagnostic capabilities of these 2 tools as well as technical aspects of both procedures and preparation.

Current status of capsule endoscopy through a whole digestive tract

More than a decade has passed since small-bowel capsule endoscopy (CE) was first reported. Small-bowel CE is a non-invasive tool that allows visualization of the entire small-intestinal mucosa and facilitates detection of small-intestinal abnormalities. Several studies have shown benefit of small-bowel CE for certain disorders. Because it is non-invasive, CE has been applied to other organs including the esophagus, stomach, and colon. The main indications for esophageal CE (ECE) are screening for gastroesophageal reflux disease/Barrett's esophagus, and esophageal varices. However, the clinical benefit of ECE is unconfirmed. Magnetically guided CE (MGCE) was developed to visualize the gastric mucosa. MGCE is a new concept with room for improvement of capsule navigation and the preparation protocol. Recently, two new small-bowel CE tools were released. First-generation colon CE (CCE-1) has moderate sensitivity and specificity compared with colonoscopy for colorectal neoplasia surveillance. To obtain higher accuracy, a second-generation CCE (CCE-2) was developed with a high sensitivity for detecting clinically relevant polypoid lesions. A possible application of CCE is for inflammatory bowel disease. In the near future, CE may include diagnostic and therapeutic functions such as magnifying endoscopy systems, targeted biopsy forceps, and drug delivery systems.

Screening for Barrett's esophagus: results from a population-based survey

BACKGROUND

Screening for Barrett's esophagus (BE) and adenocarcinoma (EAC) is controversial, but interest remains in finding the optimal method. Attitudes on screening within the community are unknown. We aimed to assess these attitudes via a survey.

STUDY

A mixed-mode survey was conducted in adults >50 years to assess awareness regarding BE, willingness to participate in screening, and preferences regarding method of screening. Methods evaluated were sedated endoscopy (sEGD), unsedated transnasal endoscopy (uTNE) and video capsule (VCE).

RESULTS

A total of 136 from 413 (33%) adults responded [47% males, mean (SD) age 63 (10.2) years], and 26% of responders knew of BE at baseline. After reading the information on BE, 72% were interested in screening. A history of undergoing screening tests and GI symptoms were predictive of interest. Unsedated techniques were preferred by 64% (VCE: 56% and uTNE: 8%) versus sEGD (36%).

CONCLUSIONS

The majority of adults were willing to undergo screening for BE/EAC, with a preference for unsedated techniques.

Oesophageal capsule endoscopy versus oesophago-gastroduodenoscopy for the diagnosis of recurrent varices: a prospective multicentre study

BACKGROUND

Oesophago-gastroduodenoscopy is the standard method for the diagnosis of recurrent oesophago-gastric varices after endoscopic treatment and eradication. The aim of this study was to evaluate the PillCam Eso capsule endoscopy in this setting.

METHODS

Prospective, multicentre study in which patients with history of oesophageal varices treated by band ligation underwent PillCam Eso capsule and oesophago-gastroduodenoscopy. Capsule recordings were blindly read by two endoscopists. Indication for a new prophylactic treatment and patient satisfaction were determined for both procedures.

RESULTS

80 patients (80% males, mean age: 57±12 years) were included, after a median delay of 16 months from last endoscopic treatment. Recurrent oesophageal varices requiring a new prophylactic treatment were detected in 26 patients (32.5%). The mean oesophageal transit time of the capsule was 153 s (range 2-930 s). Capsule sensitivity, specificity, negative and positive predictive values for indication of new prophylactic treatments were 65%, 83%, 83%, and 65%, respectively. Capsule adequately classified 77.5% of the patients for prophylaxis indication. Inter-observer concordance for capsule readings was 88% for the prophylaxis indication.

CONCLUSION

This study demonstrates that accuracy of PillCam Eso capsule for the diagnosis of recurrent oesophageal varices after endoscopic eradication is suboptimal. PillCam Eso capsule might therefore be proposed in patients unable or unwilling to undergo oesophago-gastroduodenoscopy.

Screening pre-bariatric surgery patients for esophageal disease with esophageal capsule endoscopy

AIM: To determine if esophageal capsule endoscopy (ECE) is an adequate diagnostic alternative to esophagogastroduodenoscopy (EGD) in pre-bariatric surgery patients.

METHODS: We conducted a prospective pilot study to assess the diagnostic accuracy of ECE (PillCam ESO2, Given Imaging) vs conventional EGD in pre-bariatric surgery patients. Patients who were scheduled for bariatric surgery and referred for pre-operative EGD were prospectively enrolled. All patients underwent ECE followed by standard EGD. Two experienced gastroenterologists blinded to the patient’s history and the findings of the EGD reviewed the ECE and documented their findings. The gold standard was the findings on EGD.

RESULTS: Ten patients with an average body mass index of 50 kg/m² were enrolled and completed the study. ECE identified 11 of 14 (79%) positive esophageal/gastroesophageal junction (GEJ) findings and 14 of 17 (82%) combined esophageal and gastric findings identified on EGD. Fisher’s exact test was used to compare the findings and no significant difference was found between ECE and EGD (P = 0.64 for esophageal/GEJ and P = 0.66 for combined esophageal and gastric findings respectively). Of the positive esophageal/GEJ findings, ECE failed to identify the following: hiatal hernia in two patients, mild esophagitis in two patients, and mild Schatzki ring in two patients. ECE was able to identify the entire esophagus in 100%, gastric cardia in 0%, gastric body in 100%, gastric antrum in 70%, pylorus in 60%, and duodenum in 0%.

CONCLUSION: There were no significant differences in the likelihood of identifying a positive finding using ECE compared with EGD in preoperative evaluation of bariatric patients.

Comparative evaluation of esophageal Barrett's epithelium through esophageal capsule endoscopy and methylene blue chromoendoscopy

BACKGROUND

Patients presenting with Barrett's esophagus (BE) should be under life-long surveillance in an attempt to detect cancer in its early stages. Esophageal capsule endoscopy (ECE) is a new technique that enables a noninvasive evaluation of the esophagus.

AIMS

To evaluate ECE effectiveness compared with methylene blue (MB) chromoendoscopy for the detection of esophageal lesions in which there was suspicion of cancer, the length and pattern of BE, and the presence of hiatal hernia.

MATERIAL AND METHODS

Twenty-one patients with BE who underwent Nissen fundoplication and had a follow-up period of more than five years were prospectively enrolled in the study. The patients underwent ECE and chromoendoscopy with MB performed by different physicians who were blinded to each of the procedures.

RESULTS

ECE sensitivity, negative predictive value, and accuracy were 100%, 100%, and 79%, respectively, for the detection of esophageal lesions suspected of cancer. ECE accuracy in assessing BE length was 89% and in the evaluation of finger-like projections, circumferential BE, and mixed BE was 74%, 79%, and 74%, respectively. In relation to hiatal hernia detection, ECE sensitivity was 43% and its accuracy was 74%.

CONCLUSIONS

ECE appears to be a good method for detecting lesions in which there is suspicion of esophageal cancer and it had modest results in regard to the accurate identification of BE length and pattern. ECE is not a good method for detecting hiatal hernia. Further studies are needed in order to define the definitive role of ECE in BE monitoring.

Screening and risk stratification for Barrett's esophagus: how to limit the clinical impact of the increasing incidence of esophageal adenocarcinoma

Barrett's esophagus (BE) and gastroesophageal reflux disease are the strongest risk factors for esophageal adenocarcinoma. To reduce the clinical impact of this disease, endoscopic screening to detect BE has been proposed and nonendoscopic diagnostic techniques are under investigation. Because screening would result in new diagnoses of BE and additional costs related to endoscopic surveillance, novel tools for risk stratification are also warranted. Dysplasia is the gold standard for risk stratification. Molecular biomarkers may provide a more objective and reproducible estimation of the individual risk, and further prospective studies are required as a prelude to introducing biomarkers into routine clinical practice.

Screening for oesophageal cancer

Oesophageal cancer is a global health problem with high mortality due to the advanced nature of the disease at presentation; therefore, detection at an early stage significantly improves outcome. Oesophageal squamous-cell cancer is preceded by dysplasia and oesophageal adenocarcinoma is preceded by Barrett's oesophagus, which progresses to cancer via intermediate dysplastic stages. Screening to detect these preneoplastic lesions has the potential to substantially reduce mortality and morbidity. However, the risks and benefits of such programmes to individuals and to society need to be carefully weighed. Endoscopic screening is invasive, costly and error prone owing to sampling bias and the subjective diagnosis of dysplasia. Non-endoscopic cell-sampling methods are less invasive and more cost effective than endoscopy, but the sensitivity and specificity of cytological assessment of atypia has been disappointing. The use of biomarkers to analyse samples collected using pan-oesophageal cell-collection devices may improve diagnostic accuracy; however, further work is required to confirm this. The psychological and economic implications of screening as well as the feasibility of implementing such programmes must also be considered.

Population screening for barrett esophagus: a prospective randomized pilot study

OBJECTIVE

To assess the feasibility of unsedated transnasal endoscopy (uTNE) and video capsule endoscopy (VCE) as alternatives to sedated endoscopy (sEGD) as screening tools for Barrett esophagus (BE) and to obtain preliminary estimates of participation rates for sEGD, uTNE, and VCE when used for community BE screening in a population cohort.

PATIENTS AND METHODS

From February 1, 2009, to May 31, 2010, patients from Olmsted County, Minnesota, who were older than 50 years and had no history of known BE were randomized (stratified by age, sex, reflux symptoms noted in a validated questionnaire) into 3 groups for esophageal evaluation with sEGD, uTNE, or VCE. Participation rates and safety profiles were estimated.

RESULTS

We contacted 127 patients to recruit 20 for each procedure arm (60 total). The probability of participation was 38% (95% confidence interval [CI], 26%-51%) for sEGD, 50% (95% CI, 35%-65%) for uTNE, and 59% (95% CI, 42%-74%) for VCE. Both uTNE and VCE were well tolerated without adverse effects. BE was identified in 3 patients and esophagitis in 8.

CONCLUSION

Unsedated techniques may be acceptable, feasible, and safe alternatives to sEGD to screen for BE in the community.

TRIAL REGISTRATION

clinicaltrials.gov identifier: NCT00943280.

Developing a nonendoscopic screening test for Barrett's esophagus

Barrett's esophagus (BE) arises as a complication of chronic gastro-esophageal reflux disease and is the precursor lesion for esophageal adenocarcinoma. The prevalence of esophageal adenocarcinoma has been increasing in Western countries and the overall prognosis from this cancer remains dismal. Surveillance for BE is highly controversial since although early cancer detection through surveillance programs benefits individuals, surveillance has not been proven to reduce population mortality from the disease. One factor contributing to this apparent paradox is that an estimated >80% cases of BE are undiagnosed and, therefore, do not have the benefit of surveillance. Some form of screening modality is required to achieve more comprehensive detection of BE, which in turn, may lead to early detection of cancerous lesions and early intervention in order to reduce progression to invasive and symptomatic cancer. The advent of endoscopic therapy makes this paradigm attractive. A number of methods could be considered for screening. These include a nonendoscopic sampling method using a Cytosponge that needs to be coupled with a biomarker to obtain required levels of sensitivity and specificity. For screening to be recommended consideration needs to be given to the point of delivery, cost and acceptability to patients.

Esophageal capsule endoscopy for evaluation of patients with chronic gastroesophageal reflux symptoms: findings and its image quality

Esophageal capsule endoscopy (ECE) may offer an alternative approach to visualize esophageal lesions associated with gastroesophageal reflux (GER) disease. The objective of this study was to report the ECE findings in patients with GER symptoms and validate a new scoring system to assess ECE video quality. Five hundred two ECE were performed in patients with GER symptoms. We devised a new grading scale called ECE Utility score to assess the quality of images using five different parameters: anatomic landmarks visualized, esophageal transit time, image quality, illumination, and artifacts. The ECE cases were independently scored by two interpreters in a randomized, blinded fashion. Reflux esophagitis was diagnosed via ECE in 254 patients (50.5%). We identified 12 cases (2.4%) with suspected Barrett's esophagus and all of them had endoscopic evidence of Barrett's esophagus on esophagogastroduodenoscopy. Histologic confirmation Barrett's esophagus was found in six patients and dysplasia was found in one patient. From the 502 cases, mean ± standard deviation total ECE Utility score was 8.89 ± 0.96 for interpreter 1 and 8.96 ± 0.93 for interpreter 2. The concordance rate between the two interpreters for the ECE Utility score ranged from 75.9-96.8% across the parameters and the Pearson correlation rate of the total score was 0.81. ECE is shown to be a simple noninvasive valuable technique for evaluating esophageal mucosa and producing high quality images in patients with GER symptoms. ECE can help as an alternative screening tool for diagnosing Barrett's esophagus.

Barrett esophagus: an update

Many developments have been made in the field of Barrett esophagus that have tremendous clinical implications. There are new definitions of Barrett esophagus that have had an immediate clinical impact on cancer risk and screening. Of interest is the definition by the British Society of Gastroenterology, which does not require the presence of intestinal metaplasia for a diagnosis of Barrett esophagus. Imaging techniques that allow improved visualization of intestinal metaplasia at the cellular level are now being used in clinical practice. New hypotheses elucidating the progression from squamous epithelium to intestinal metaplasia have been proposed. Indeed, the crucial role that transcription factors have in the pathogenesis of Barrett esophagus has been clarified. Improved characterization of the molecular mechanisms underlying Barrett esophagus is an incentive to undertake more basic science research in this field. Such research could also help with the development of chemoprevention strategies for this precancerous condition. This Review discusses the advances in understanding of the pathogenesis, diagnosis and treatment of Barrett esophagus.

Scanning fiber endoscopy with highly flexible, 1 mm catheterscopes for wide-field, full-color imaging

In modern endoscopy, wide field of view and full color are considered necessary for navigating inside the body, inspecting tissue for disease and guiding interventions such as biopsy or surgery. Current flexible endoscope technologies suffer from reduced resolution when device diameter shrinks. Endoscopic procedures today, using coherent fiber-bundle technology on the scale of 1 mm, are performed with such poor image quality that the clinician's vision meets the criteria for legal blindness. Here, we review a new and versatile scanning fiber-imaging technology and describe its implementation for ultrathin and flexible endoscopy. This scanning fiber endoscope (SFE) or catheterscope enables high-quality, laser-based, video imaging for ultrathin clinical applications, while also providing new options for in vivo biological research of subsurface tissue and high resolution fluorescence imaging.

Screening for Barrett's Esophagus

Barrett's esophagus (BE) increases the risk for development of esophageal adenocarcinoma. Because of the rapid rise in incidence of esophageal adenocarcinoma, screening for BE with subsequent surveillance when found has been proposed as a method of early detection. Sedated endoscopy, however, is too expensive for wide spread screening. As a result, other techniques including unsedated transnasal esophagoscopy and capsule esophagoscopy have been proposed to expand screening programs.

PillCam ESO versus esophagogastroduodenoscopy in esophageal variceal screening: A decision analysis

OBJECTIVES

PillCam ESO has been evaluated as a possible strategy to screen patients with cirrhosis for esophageal varices, but current guidelines recommend patients undergo screening with esophagogastroduodenoscopy (EGD), as it is currently the gold standard. Although recent data have suggested that PillCam ESO may be an acceptable alternative for screening, there is limited data on its cost-effectiveness compared with other screening modalities. This study was performed to compare the cost-effectiveness of PillCam ESO versus EGD for esophageal variceal screening.

METHODS

Markov models were constructed to compare 2 screening strategies: PillCam ESO versus EGD. In each arm, patients were followed for a time horizon of 15 years in 1-year transition intervals. All variables, transition probabilities, and costs were derived from the medical literature, and sensitivity analyses were performed on the different variables in the model.

RESULTS

Base-case analysis shows that PillCam ESO is associated with an average expected cost of $22,589 and an average expected effectiveness measure of 12.81 life-years. EGD is associated with an average expected cost of $23,083 and an average expected effectiveness measure of 12.67 life-years. PillCam ESO was found to dominate EGD as a screening strategy for patients with cirrhosis. Sensitivity analyses found several variables within the model to have influential effects on the results.

CONCLUSIONS

PillCam ESO is the dominant strategy for screening patients with cirrhosis for esophageal varices. However, based on a small difference in costs and effectiveness between each strategy, the results would suggest that PillCam ESO and EGD are essentially equivalent strategies.

Prospective, controlled assessment of the impact of formal evidence-based medicine teaching workshop on ability to appraise the medical literature

BACKGROUND

The ability to critically appraise the calibre of studies in medical literature is increasingly important for medical professionals.

AIM

This prospective controlled study evaluated the impact of a 6-h Evidence Based Medicine (EBM) Workshop on the critical appraisal skills of medical trainees.

METHODS

Individuals attended three 2-h workshops over a 3-week period, incorporating didactic lectures in statistics, clinical trial design, appraising research papers and practical examples. Appraisal skills were assessed pre- and post-training based on grading the quality of randomised control studies (level 1 evidence), cohort studies (level 2 evidence) and case-control studies (level 3 evidence) [From Oxford Centre for Evidence Based Medicine Levels of Evidence (2001), http://www.cebm.net/critical_appraisal.asp ].

RESULTS

Overall grading improved from 39% (pre-course) to 74% (post-course), P = 0.002, with grading of levels 1, 2 and 3 studies improving from 42 to 75%, 53 to 61% and 21 to 84%, respectively.

CONCLUSIONS

We conclude that a 6-h formal EBM workshop is effective in enhancing the critical appraisal skills of medical trainees.

Advances in the diagnosis of Barrett's esophagus

Barrett's esophagus is a metaplastic change in esophageal lining, characterized by the replacement of normal squamous epithelium with columnar epithelium. Barrett's esophagus is associated with a high risk of esophageal adenocarcinoma. As the incidence of esophageal adenocarcinoma has risen dramatically in developed countries, the research on Barrett's esophagus is attracting increasing attention. In this article, we will review the recent advances in the diagnosis of Barrett's esophagus.

[Future prospects in digestive endoscopy: wireless capsule endoscopy]

Since the beginning of the millennium, the development of wireless capsule endoscopy has represented a major technological advance. The capsule is ingested by the patient and images are transmitted via several sensors positioned on the skin of the patient and downloaded in a computer system. The first applications were focused on the exploration of the small bowel which was previously considered as an obscure area for conventional endoscopy. Wireless capsule endoscopy of the small bowel is now an established technique with many acknowledged indications for the diagnosis of obscure bleeding, anemia of presumed digestive origin, Crohn's disease and small bowel tumors. Recently, thanks to technological progresses, novel capsules have been developed for specific segments of the gut namely the oesophagus and the colon. Recent data suggest that these new capsules could have potential applications for the diagnosis of oesophageal varices, Barrett's oesophagus and for the screening and/or surveillance of polyps of the colon. However, further studies are required before such strategies could be approved for clinical use or even replace conventional endoscopic modalities. In the long-term, progresses in signal processing as well as in the miniaturisation of sensors or markers may lead to a new generation of endoscopic robots. This technological breakthrough may ultimately result in new concepts and change current practice of digestive endoscopy.

Sleeve string capsule endoscopy for real-time viewing of the esophagus: a pilot study (with video)

BACKGROUND

Previous studies suggest that string capsule endoscopy is feasible, safe, accurate, highly acceptable, and likely to be proven as a more cost-effective technique than conventional EGD. However, this technique needs proper high-level disinfection, and the string attachment is not easy to perform. We developed a modified esophageal capsule endoscopy, called sleeve string capsule endoscopy (SSCE).

OBJECTIVE

To assess the feasibility and safety of SSCE in the evaluation of esophageal diseases.

DESIGN

A pilot study.

SETTING

Outpatient setting in a tertiary hospital, Shanghai, China.

PATIENTS

Two healthy volunteers and 8 patients with suspected esophageal diseases were enrolled.

INTERVENTIONS

The OMOM capsule endoscope was enclosed in a small, transparent, thin, latex sleeve, with a string attached to the caudal end. Both the sleeve and the string were for single use and were discarded after completion of the procedure. Two healthy volunteers without previous EGD and 8 patients who had undergone EGD swallowed the capsules. Pictures of the esophagus were viewed in real time.

MAIN OUTCOME MEASUREMENTS

Discomfort associated with the procedure, quality, and diagnostic value of the pictures were documented. In addition, patient preference between SSCE and conventional EGD was recorded.

RESULTS

SSCE was successfully carried out in the 10 subjects. The procedures were easy and safe to perform. No sleeves and strings were disrupted or broken, and no capsule was lost. The mean overall discomfort score during SSCE in the 8 patients was 2.88 (range 2-5). Pictures generated during SSCE were generally of high quality and produced identical diagnoses to those obtained by EGD in all 8 patients. In addition, all the 8 patients preferred SSCE to EGD.

LIMITATIONS

This was a single-center nonrandomized study with a small sample size.

CONCLUSIONS

SSCE was a feasible, easy-to-operate, and safe method for the diagnosis of esophageal diseases without the need for disinfection. SSCE appears to possess the same diagnostic capacity as that of EGD.

Capsule endoscopy of the esophagus

Video capsule endoscopy has acquired wide clinical acceptance since its the US Food and Drug Administration approval in 2001. Recently, the technology of video capsule endoscopy has been adapted to other organs in the gastrointestinal tract, including the esophagus and colon. In this review, we discuss esophageal capsule endoscopy (ECE)-the procedure, its indications, contraindications, safety, and future applications. ECE is a minimally invasive procedure that uses special video capsules with ability to acquire images from 2 cameras with high image storing speed of 14 to 18 frames per second. A special ingestion procedure allows for prolonged esophageal transit time and an optimized view of the gastroesophageal junction. ECE has been shown to have moderately high sensitivity and accuracy in the diagnosis and surveillance of Barrett esophagus in patients with gastroesophageal reflux disease but has not demonstrated superiority to esogastroduodenoscopy in cost-effectiveness models. In patients with portal hypertension, ECE has a sensitivity of 63% to 100% for screening of esophageal varices, but does not seem to be superior to esogastroduodenoscopy in its cost-effectiveness. No serious complications have been reported after ECE although a low rate of esophageal capsule retention (0.7% to 2.2%) has been reported, usually because of unsuspected esophageal strictures. Contraindications to capsule endoscopy include known or suspected gastrointestinal and esophageal obstruction, strictures, or fistulas, intestinal pseudoobstruction, and children under 10 years of age. It is expected that improvements in imaging technology will improve the accuracy of ECE with the development of immunological-based and chemical-based diagnostic capabilities.

Changes in screening, prognosis and therapy for esophageal adenocarcinoma in Barrett's esophagus

PURPOSE OF REVIEW

Significant changes in concepts of managing Barrett's esophagus have led to change in the recommendations concerning screening, surveillance, biomarkers, and therapies in this condition over the past several years. We summarize the important changes in this regard.

RECENT FINDINGS

Narrow band imaging and esophageal capsule endoscopy are alternative methods to screen for Barrett's esophagus. Narrow band imaging provides clear visualization of the mucosal pit patterns and vascular patterns, which improve the diagnostic value for specialized intestinal mataplasia. Esophageal capsule endoscopy is a new potential tool that allows a direct noninvasive visualization of esophagus. Research efforts are currently directed towards risk stratification of patients and biomarkers have been developed to predict development of esophageal adenocarcinoma. Recent studies have reported that frequent loss of heterozygosity (LOH) as well as allelic imbalances in chromosomes in esophageal adenocarcinoma. Fluorescent in-situ hybridization technique, which uses fluorescently labeled DNA probes to detect chromosomal alterations in cells, obtained from cytology specimens has been developed. It showed more sensitive and specific for abnormalities than PCR based techniques. Currently, many studies support the concept of endoscopic elimination of dysplastic lesions in the esophagus by a mucosal ablation therapy. Photodynamic therapy and radiofrequency ablation are recently developed, emerging techniques.

SUMMARY

Recent advances in screening; prognostication and therapy for esophageal adenocarcinoma in Barrett's esophagus have brought a significant new insight in clinical practices and will eventually ensure better patients outcomes.

A meta-analysis of the diagnostic accuracy of esophageal capsule endoscopy for Barrett's esophagus in patients with gastroesophageal reflux disease

OBJECTIVES

To evaluate the diagnostic accuracy of esophageal capsule endoscopy (ECE) for Barrett's esophagus (BE) in patients with gastroesophageal reflux disease (GERD).

METHODS

Literature was searched for blinded studies evaluating the diagnostic accuracy of ECE for BE in patients with GERD. Meta-analysis was carried out to calculate pooled sensitivity and specificity of ECE for diagnosis of BE. Subgroup analysis was also carried out based on the reference standard used.

RESULTS

Nine studies comprising a total of 618 patients met the inclusion criteria. The pooled sensitivity and specificity of ECE for the diagnosis of BE for all studies were 77 and 86% respectively. The pooled sensitivity and specificity of ECE for the diagnosis of BE using esophagogastroduodenoscopy (EGD) as the reference standard were 78 and 90%, respectively; using histologically confirmed intestinal metaplasia (IM) as the reference standard pooled sensitivity and specificity were 78 and 73%, respectively. Statistical heterogeneity was not evident among studies for sensitivity results (P=0.270, I(2)=19), but heterogeneity was present for specificity results (P<0.001, I(2)=74). There was no evidence of publication bias. The ECE was found to be safe and had a high rate of patient preference.

CONCLUSIONS

Capsule endoscopy of esophagus has a moderate sensitivity and specificity for the diagnosis of BE in patients with GERD. The EGD remains the modality of choice for evaluation of suspected BE.

Barrett's oesophagus

Barrett's oesophagus is a metaplastic change of the lining of the oesophagus, such that the normal squamous epithelium is replaced by specialised or intestinalised columnar epithelium. The disorder seems to be a complication of chronic gastro-oesophageal reflux disease, although asymptomatic individuals might also be affected, and it is a risk factor for the development of oesophageal adenocarcinoma, a cancer with rapidly increasing incidence in developed societies. We review the presentation, epidemiology, and risk factors for this condition. We discuss the molecular changes necessary for the development of Barrett's oesophagus and its progression to cancer, and new strides in both the endoscopic detection of the lesion and the treatment of dysplastic disease. Also, we assess the effectiveness of efforts to screen patients at risk of Barrett's oesophagus, and whether such efforts avert cancer death. We conclude with a discussion of future directions for research, focusing on treatment of early neoplasia, and modifications of current practices to show our evolving understanding of this condition.

Optimal approach to obtaining mucosal biopsies for assessment of inflammatory disorders of the gastrointestinal tract

Endoscopic evaluation and mucosal biopsy analysis have assumed important roles in the clinical management of patients with symptoms related to the gastrointestinal tract. Several common inflammatory diseases, including eosinophilic esophagitis, Barrett's esophagus, Helicobacter pylori infection, celiac disease, lymphocytic colitis, collagenous colitis, and inflammatory bowel disease, may display a patchy or discontinuous distribution and, thus, multiple mucosal samples may be required to obtain diagnostic tissue in some cases. Not surprisingly, clinicians and pathologists are increasingly challenged to determine the optimum number of procedures and tissue samples necessary to detect, or exclude, the presence of inflammatory disorders of the gastrointestinal tract. Unfortunately, clinical practice varies widely with respect to tissue sample procurement in the evaluation of these disorders, particularly when the endoscopic appearance of the gastrointestinal mucosa is normal or shows only minimal changes. Guidelines concerning the appropriate number of tissue samples are well established for some diseases, such as Barrett's esophagus and chronic gastritis, but are not clear in other instances. The purpose of this review is to discuss the available literature pertaining to appropriate endoscopic sampling in the assessment of medical diseases of the gastrointestinal tract, and to develop recommendations regarding the clinical evaluation of common gastrointestinal disorders.

Screening, surveillance, and prevention for esophageal cancer

The incidence of esophageal cancer, especially esophageal adenocarcinoma, is increasing and its high mortality rate is a notable fact. Improving survival rates of this disease depend on earlier detection through screening and surveillance; however, standard diagnostic modalities, such as endoscopy with biopsy, have several limitations as screening tools, including low negative predictive value and relatively high cost. Recently developed biomarkers such as FISH and improved imaging techniques, may help overcome current problems and provide improved screening and surveillance for esophageal cancer.

Barrett's esophagus in 2008: an update

With the rising incidence and overall poor prognosis of esophageal adenocarcinoma (EA) there is great interest in furthering our understanding of Barrett's esophagus, the precursor lesion for most cases of EA. The best available evidence from true population-based analysis suggests that the prevalence of Barrett's is 1.6%. In addition, nearly half of the patients with Barrett's are asymptomatic. Several risk factors for development of Barrett's have been identified including gastro-esophageal reflux disease (GERD), central obesity, H. pylori eradication, and male gender. The precise incidence of progression from Barrett's to esophageal adenocarcinoma is not known, but it probably is less than 0.5% per year, and our ability to predict who is at highest risk for progression remains poor. The degree of dysplasia is currently used as a marker for risk of progression to cancer though there is increasing evidence that biomarkers and level of genetic instability may provide better predictive measures. Intensive acid-suppression and COX-2 inhibition are potential strategies to reduce the risk of progression, though definitive studies are needed. Endoscopic surveillance remains the mainstay of management for non-dysplastic and low grade dysplasia Barrett's. The advent of various endoscopic ablative therapies has provided a promising alternative to surgery for Barrett's patients with high grade dysplasia (HGD).

In vivo microrobots for natural orifice transluminal surgery. Current status and future perspectives

The possibility to operate inside the peritoneal cavity through small holes performed in hollow organs that is presented by Natural Orifice Transluminal Endoscopic Surgery (NOTES) represents a major paradigm shift in general surgery. While this new approach seems very appealing from patients' perspectives because it eliminates completely abdominal wall aggression and promises to reduce postoperative pain, it is very challenging for surgeons because of the major constraints imposed by both the mode of access and the limited technology currently available. For this reason NOTES applications at the present time are performed by only a few surgeons and mainly to perform non-complex procedures. While new devices are under development, many of them are trying mainly to simply improve current endoscopic platforms and seem not to offer breakthrough solutions. The numerous challenges introduced by natural orifice approaches require a radical shift in the conception of new technologies in order to make this emerging operative access safe and reproducible. The convergence of several enabling technologies in the field of miniaturization, communication and micro-mechatronics brings the possibility to realize on a large scale the revolutionary concept of miniature in vivo co-operative robots. These robots provide vision and task assistance without the constraints of the entry incision and have been shown in experimental settings to possess many qualities that could be ideal to partner with Natural Orifice Surgery. This article explores the current status of microrobotics as well as presents potential future scenarios of their applications in NOTES.

Esophageal capsule endoscopy

Capsule endoscopy is now considered as the first imaging tool for small bowel examination. Recently, new capsule endoscopy applications have been developed, such as esophageal capsule endoscopy and colon capsule endoscopy. Esophageal capsule endoscopy in patients with suspected esophageal disorders is feasible and safe, and could be also an alternative procedure in those patients refusing upper endoscopy. Although large-scale studies are needed to confirm its utility in GERD and cirrhotic patients, current results are encouraging and open a new era in esophageal examination.

Capsule endoscopy for the detection of oesophageal mucosal disorders: a comparison of two different ingestion protocols

OBJECTIVE

To assess the accuracy of a new ingestion protocol for capsule endoscopy (CE) in evaluating patients with gastro-oesophageal reflux disease (GORD).

METHODS

Oesophago-gastroduodenoscopy (OGD) was performed 1 week prior to CE. The first 28 subjects swallowed the capsule following the original ingestion protocol (OIP) and the subsequent 30 subjects following a simplified ingestion protocol (SIP). CE videos were reviewed by two independent investigators who were blinded to the OGD findings.

RESULTS

Of 48 patients included, 24 were diagnosed with reflux oesophagitis (67% male, mean age 49.5+/-13 years) and 24 with Barrett oesophagus (BO) (88% male, 55.6+/-10 years) by OGD. In addition, 10 asymptomatic healthy controls (50% male, 45.8+/-7.1 years) were included. Oesophageal transit time was faster in patients using the SIP compared to the OIP (126+/-26 s versus 214+/-33; p=0.04). Complete evaluation of the Z-line was possible in 19/28 (68%) of the OIPs compared to 28/30 (93%) of the SIPs (p=0.04). Sensitivity for detecting any oesophageal abnormality was higher in the SIP group than in the OIP group (97% versus 89%; p=0.11). Overall, CE detected oesophagitis in 22/24 patients (sensitivity, 92%; specificity, 88%) and BO in 23/24 patients (sensitivity, 96%; specificity, 91%). Furthermore, 41/44 (93%) preferred CE over OGD and experienced less discomfort and pain during CE.

CONCLUSION

CE is an accurate method for detecting mucosal oesophageal abnormalities. The new ingestion protocol improves the visualization of the Z-line, which is likely to increase the diagnostic yield of CE.

Should patients with Barrett's oesophagus be kept under surveillance? The case for

Oesophageal adenocarcinoma is associated with high mortality rates and its incidence is increasing more rapidly than any other gastrointestinal cancer in the Western world. Several factors, including gastro-oesophageal reflux disease, smoking, alcohol and male gender, are associated with oesophageal adenocarcinoma but none can be used to identify accurately those individuals who will develop adenocarcinoma. It is generally accepted that oesophageal adenocarcinoma arises predominantly in Barrett's oesophagus and it is arguable that Barrett's oesophagus is currently the only clinically useful predictor of oesophageal adenocarcinoma. Surveillance - periodic testing to detect adenocarcinoma or its precursor, high grade dysplasia - is widely recommended for patients with Barrett's oesophagus with the aim of reducing mortality from oesophageal adenocarcinoma. The annual incidence of oesophageal adenocarcinoma in patients with Barrett's oesophagus is 0.5%-1.0% although there is marked variation between studies, attributable variously to publication bias, concurrent acid suppression therapy and differences in patient characteristics. There is limited evidence that surveillance reduces the incidence of oesophageal adenocarcinoma or consequent mortality and the cause of death for patients undergoing surveillance is often unrelated to oesophageal disease. There are, nonetheless, observational studies which suggest that surveillance is associated with earlier detection of malignancy and a reduction in mortality; in addition, data from modelling studies suggest that surveillance can be cost-effective. Furthermore, the advent of new, non-surgical treatments (endoscopic mucosal resection, photodynamic therapy, argon plasma coagulation) for high grade dysplasia and early cancer has reduced the risks associated with therapy for disease detected during surveillance. Surveillance programs have high drop out rates and, for patients who continue surveillance, adherence to standard, published protocols is highly variable. The establishment of specialist Barrett's oesophagus surveillance programs, with coordinator support, has considerable potential to improve adherence to current guidelines, pending the acquisition and publication of data from ongoing studies of chemoprophylaxis and surveillance in the management of Barrett's oesophagus. In consequence, although there is a paucity of data providing unequivocal demonstration of benefit, there is no proof that surveillance is ineffective. It is, therefore, appropriate to offer surveillance for Barrett's oesophagus in accordance with locally-applicable published guidelines after a full informed discussion of the risks and benefits of surveillance and therapy; continued participation should be reviewed regularly to accommodate changes in the patient's health and expectations.